![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)
MoFeは,窒素酵素MoFeタンパク質の4電子減少 (E4) の中間体によって水素結合に関与していますか?
Dmitriy Lukoyanov1, Zhi-Yong Yang, Dennis R Dean
1Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
Journal of the American Chemical Society
|February 4, 2010
まとめ
この研究は,モリブデン (Mo) がモリブデン-鉄共因子 (FeMo-co) のE(4) 中間状態の水素を結合しないという直接的な証拠を提供します. Moではなく,鉄 (Fe) イオンが,触媒周回中の水素結合に関与しています.
科学分野:
- バイオケミストリーとバイオ有機化学
- 酵素触媒は,酵素触媒として作用する.
- 窒素固定に関する研究
背景:
- モリブデン鉄共因子 (FeMo-co) は,窒素酵素活性に中心的な役割を果たしています.
- FeMo-co内の基板相互作用を理解することは,窒素固定機構の解明に不可欠です.
- 以前の研究では,触媒作用中の水素結合におけるモリブデンムの役割が仮定されていた.
研究 の 目的:
- 触媒回転中の基板相互作用におけるモリブデンの関与の直接的な実験的証拠を提供すること.
- FeMo-co.のE(4) の中間状態におけるヒドリド結合におけるモリブデンの役割を決定する.
- モリブデンの影響を受けたFeMo-coの電子的および幾何学的性質を調査するために.
主な方法:
- アルゴンの下でのH (−−+) 還元過程でα-70 (−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
- 電子パラマグネティック共振 (EPR) と電子核二重共振 (ENDOR) のスペクトロスコーピー.
- 精度の高い高精度カップリング測定のために (95) Moで同位素濃縮.
主要な成果:
- N(2) の還元のために活性化されたE(4) の中間状態は,FeMo-co.に結合した2つの水素を含んでいる.
- ENDORの測定は,E (4) 状態におけるMo (deK) のベクトル結合係数が非常に小さいことを明らかにした.
- これはMoがヒドリド結合に参加していないことを示し,Feイオンだけが関与している.
結論:
- モリブデンは,触媒的に重要な中介物質であるE (((4) の水素を直接結合しません.
- FeMo-co内の鉄イオンは,触媒の回転中に水素結合を担っている.
- ハイドリドを結合しないにもかかわらず,Moの結合反応は,FeMo-coの性質を調節する上で重要な役割を果たしていることを示唆しています.
さらに関連する動画
12:08Catalytic Reactions at Amine-Stabilized and Ligand-Free Platinum Nanoparticles Supported on Titania During Hydrogenation of Alkenes and Aldehydes
Published on: June 24, 2022
10:52Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
Published on: July 27, 2022
関連する概念動画
00:55Nitriles to Amines: LiAlH4 Reduction
Nitriles are reduced to amines in the presence of strong reducing agents like lithium aluminum hydride through a typical nucleophilic acyl substitution. The reaction requires two equivalents of the reducing agent. The reducing agent acts as a source of hydride ions.
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
As shown below, the mechanism involves three steps. Firstly, the hydride ion acting as a nucleophile attacks the nitrile carbon to form an anion. In the second step, a second equivalent of the hydride ion attacks the anion to...
02:55Exceptions to the Octet Rule
Many covalent molecules have central atoms that do not have eight electrons in their Lewis structures. These molecules fall into three categories:
01:29Preparation of Amines: Reduction of Oximes and Nitro Compounds
Oximes can be reduced to primary amines using catalytic hydrogenation, hydride reduction, or sodium metal reduction. The reduction of aliphatic and aromatic nitro compounds to primary amines takes place by either catalytic hydrogenation or by using active metals like Fe, Zn, and Sn in the presence of an acid.
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
Though catalytic hydrogenation can reduce nitrobenzenes, the reduction is nonselective in the presence of other functional groups. For instance, if nitrobenzene contains an aldehyde group,...
01:04Hydrogen Bonds
A hydrogen bond is formed when a weakly positive hydrogen atom already bonded to one electronegative atom (for example, the oxygen in the water molecule) is attracted to another electronegative atom from another polar molecule, such as water (H2O), hydrogen fluoride (HF), or ammonia (NH3). The huge electronegativity difference between the H atom (2.1) and the atom to which it is bonded (4.0 for an F atom, 3.5 for an O atom, or 3.0 for an N atom), combined with the very small size of an H atom...
00:26Hydrogen Bonds
Hydrogen BondsHydrogen bonds are weak attractions between atoms that have formed other chemical bonds. One of these atoms is electronegative, like oxygen, and has a partial negative charge. The other is a hydrogen atom that has bonded with another electronegative atom and has a partial positive charge.Hydrogen Bonds Control the World!Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are...
02:51Metal-Ligand Bonds
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...